answer: tighter spreads. We moved from 1/16 (was it? I am not a US trader...-> pennies, which has been good for spreads). The same will happen when people can put in orders at sub pennies.
Quote from Nofear777:
But theres nothing wrong with the smallest increment being pennies. What benefit does subpenny for everyone have over subpenny for no one? Like you said, earlier, last thing we need is more market fragmentation.
Maybe you have thought of a reason that I have not.
As far as being transparent and on equal footing with everyone, we are 100% on the same page .